Overview
Polystyrene microsphere probes are synthetic polymer particles engineered for precision applications in life sciences and nanotechnology. These spherical particles, typically ranging from 100 nm to 100 µm in diameter, are manufactured via emulsion or dispersion polymerization to achieve narrow size distributions. Their uniform morphology and customizable surface chemistry (e.g., carboxylation, amination) enable covalent attachment of biomolecules like antibodies or DNA. In B2B contexts, these probes serve as essential tools for quantitative analysis, acting as reference standards in flow cytometry or super-resolution microscopy. Commercial grades include plain, fluorescent (FITC, TRITC), and magnetic variants, with certifications available for ISO 17025-accredited calibration.
Physical and Chemical Properties
The probes exhibit high refractive index (1.59 at 589 nm), making them optically distinguishable in imaging systems. Their density (~1.05 g/cm³) allows stable aqueous suspensions when properly surfactant-coated. Thermal stability extends to 200°C, though functionalized variants may degrade at lower temperatures. Surface charge (zeta potential) varies with modification: plain PS shows −30 to −50 mV, while carboxylated versions reach −40 to −60 mV in pH 7 buffers. Fluorescent types maintain stable emission spectra with quantum yields up to 90% for proprietary dyes. Shelf life is typically 12–24 months when stored at 4°C without freeze-thaw cycles.
Main Applications
In diagnostics, these probes function as capture beads in multiplexed immunoassays (e.g., Luminex xMAP technology), where different bead sets distinguish analytes. Their size uniformity ensures reproducible flow cytometry results, with NIST-traceable versions used for instrument calibration. Material scientists employ them as templates for porous structure fabrication or as tracers in rheology studies. In drug delivery research, surface-modified microspheres model nanoparticle behavior. A emerging application is as fiducial markers in 3D bio-printing, where their optical contrast aids layer alignment.
Safety and Storage
While non-toxic, dry powders require handling with NIOSH-approved N95 masks to prevent respiratory irritation. Aqueous suspensions may contain preservatives (e.g., sodium azide ≤0.1%) requiring disposal as chemical waste. Avoid sonication beyond 30 seconds to prevent particle fracture. Long-term storage demands protection from UV degradation (amber vials for fluorescent types) and microbial growth (0.02% sodium azide for suspensions). Centrifugation during processing should not exceed 20,000×g to maintain dispersion stability. Spill cleanup involves wet wiping with ethanol for powders or absorption with inert materials for liquids.
B2B Procurement Guide
Industrial buyers should verify: 1) Coefficient of variation (CV) ≤5% for critical applications, 2) Batch-specific certificates of analysis including DLS/SEM size data, 3) Endotoxin levels (<0.1 EU/mL for in vitro diagnostics), and 4) Compatibility with target buffers (e.g., PBS may aggregate carboxylated beads). Bulk orders (1kg+) often qualify for 15–30% discounts, though lead times extend for custom modifications. OEM suppliers like Thermo Fisher, Merck, and Bangs Laboratories dominate the market, while Chinese manufacturers (e.g., BaseLine ChromTech) offer cost-competitive alternatives for non-GMP applications. Request free evaluation samples to test batch homogeneity before large purchases.
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- 主营：嵌段共聚物、合成磷脂、荧光染料、PEG、点击化学、量子点